DISCRETE encapsulated solitary pulmonary granulomas of the type exemplified by Figures 1 and 2 have long been considered due to infection by the tubercle bacillus and, in fact, are commonly labeled "tuberculoma" by clinician, radiologist, and pathologist alike. Such lesions are usually discovered incidentally on "routine" roentgenographic examinations of asymptomatic subjects. When there is calcification, with or without a distinctly laminated pattern, the roentgenologist is often able to predict the inflammatory character of the lesions.1 Other lesions, presumably of shorter duration, may present a perfectly homogeneous opacity in the x-ray film and may therefore be confused with a primary or metastatic neoplasm (Fig.3). The proportion of these "coin lesions" which prove to be granulomas (so-called tuberculomas) after surgical removal has been reported as varying from 25% (Davis and Klepser2) to 87% (Mahon and Forsee3) depending on the nature of the hospital population and individual criteria for inclusion